Liquid spray head for producing rectangular spray patterns

ABSTRACT

A nozzle for spraying liquids is provided. In a useful example, cooking oil is sprayed into baking pans using a conduit which discharges the oil at a center point between two concentric closely-spaced circular discs, in parallel horizontal planes, the lower disc being smaller than the upper disc, there being a large number of small air passages in a circular pattern extending downwardly through the upper disc, all around the border of the lower disc. The oil flows radially out from between the discs, and is impinged upon by air under pressure issuing downwardly from the air passages. Thereby the oil film is largely atomized and sprayed downwardly. Oil from between the discs not so atomized reaches the internal surface of a conical skirt, and is guided thereby down the skirt and off the lower edge thereof in an atomized condition. A solid cone of atomized oil particles is thereby delivered downwardly in a burst of only a few hundredths of a second. A specially contrived skirt produces a square or rectangular pattern of the sprayed liquid.

United States Patent [191 Hanson, Jr.

[451 Aug. 27, 1974 [54] LllQUlD SPRAY HEAD FOR PRODUCING REQTANGULAR SPRAY PATTERNS Primary Examiner-Robert S. Ward, Jr. [75] Inventor: Harold W. Hanson, J52, Newport Attorney Agent or FlrmfiFOrresi Lmy B h, C l'f. we 57 ABSTRACT [73] Asslgnee' ay L05 Angekb A nozzle for spraying liquids is provided. In a useful example, cooking oil is sprayed into baking pans using [22] Filed: Mar. 23, 1973 a conduit which discharges the oil at a center point between two concentric closelyspaced circular discs, in [21] Appl' 344074 parallel horizontal planes, the lower disc being smaller than the upper disc, there being a large number of [52] US. Cl 239/520, 239/524, 239/601, small air passages in a circular pattern extending 239/DIG. 1 downwardly through the upper disc, all around the [51] Int. Cl B05b 1/02, B05b 15/04 border of the lower disc. The oil flows radially out [58] Field of Search 239/DIG. 1, 518, 520, 524, from between the discs, and is impinged upon by air 239/601, 548, 498, 499, 552 under pressure issuing downwardly from the air passages. Thereby the oil film is largely atomized and [56] References Cited sprayed downwardly. Oil from between the discs not UNITED STATES PATENTS so atomized reaches the internal surface of a conical 919 737 4H909 Loomis et a! 239/5 X skirt, and is guided thereby down the skirt and off the l ggosso 10/1932 Dietsch lower edge thereof in an atomized condition. A solid 10/1932 Moon cone of atomized oil particles is thereby delivered 2 59 10 19 1 downwardly in a burst of only a few hundredths of 21 2,671,693 3/1954 second. A specially contrived skirt produces a square 2,834,635 /1958 or rectangular pattern of the sprayed liquid. 3 ,029,030 4/1962 3,533,561 /1970 Henderson 239/499 x 9 Clalms, 6 Drawmg Figures LIQUID SPRAY HEAD FOR PRODUCING RECTANGULAR SPRAY PATTERNS RELATED APPLICATION This application is filed coincidently with an application filed by Beauford C. Doering, Ser. No. 344,075, filed Mar. 23, 1973, and covers and claims subject matter other than that claimed in Ser. No. 344,075.

BACKGROUND OF THE INVENTION Confining attention, for illustrative purposes, largely to the baking oil or grease application, it is common practice in bakeries to spray baking pans with a cooking oil or grease to prevent sticking. Generally, the baking pan, often on a traveling conveyor, is stopped, the spray then turned on for a short time, and the conveyor then moved on. The primary purpose of this invention is to provide a spray head which can deliver a solid cone of substantially uniformly distributed spray particles, which is modified in cross-sectional outline by a specially contrived spray control skirt, so that the initial cone merges into a pyramid, yielding a square or rectangular outline.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the invention, broadly described, a spray head is provided to which air is delivered under considerable pressure, as 30 to 80 psi, and is valved on just before the burst of spray is required. A measured charge of oil, or other liquid, is then forced through the spray head, and formed into peripherally expanding layer of radially outward flow. The air under pressure impinges on this layer of liquid and breaks it up into finely divided downwardly directed particles. The liquid which is not thus broken up continues radially outward until it is deflected downward into a spray cone by encountering the inside surfaces of a spray control skirt whose angles and contour define the central angle, or angles, of the spray cone, and also the exterior contour or perimeter thereof. This contour is a polygon, and can be rectangular, as square, or may have other forms.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a spray head in accordance with the invention, spraying atomized cooking oil into a rectangular pan on a conveyor;

FIG. 2 is a section taken in accordance with the line 2-2 of FIG. ll;

FIG. 3 is a transverse section, to an enlarged scale, taken on line 33 of FIG. 2;

FIG. 4 is a transverse section taken on line 4-4 of FIG. 3;

FIG. 5 is a perspective view of the spray control ring; and

FIG. 6 is a detail section taken in accordance with the line 6-6 of FIG. 2.

DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT The drawings show, to approximately l-to-l scale in FIG. 2 of the original bristol board, an illustrative spray device to which the present invention may be added. By this improvement, the spray can, for example, be five inches square in outline at the plane where it strikes a 5'inch square baking pan. For larger sized pans, the spray head can be enlarged accordingly; and for rectangular pans, modifications are available.

The spray device, other than for the device for controlling the outline of the spray pattern, is disclosed and claimed in the aforementioned application, filed coincidently herewith, and assigned to a common assignee, Par-Way Mfg. Co.

The spray device illustrated has :a main body 10 comprising a generally cylindrical upper part ll, screw threaded at the top, as at T2, and formed therebelow with an annular peripheral air port 13, below that with a peripherally milled external annular flange 14, and it terminates at the bottom in a tubular, externallythreaded end 15. The parts ll, l3, l4 and 15 are all coaxial. The tubular formation results from a bore 16 extending coaxially up into the end part 15; and the end part 15 is formed with a shallow counterbore l9.

Bore I6 is formed with a fillet 20 at the bottom, and meets a shallow coaxial reduced bore 22. An oil, grease, or other liquid passage 23 extends through the body 310 from the bottom of bore 22 to the bottom of a tapped counterbore 24 in said upper body part 11.

A connector fitting 26 in the nature of a cap screws onto the upper part ll of the body and extends down past annular port 13 into engagement with body flange 14. Packing rings 27 seal the air port 13. The fitting 26 has a bore 28 receiving a threaded pipe fitting 30 adapted to be screwed into bore 24, and provided with an oil, grease, or liquid passage 32 meeting the aforementioned passage 23. The fitting 30 is somewhat diagrammatically illustrated, but will be understood to comprise in practice any hydraulic fitting adapted to couple an oil supply pipe or hose to the oil passage 23 in the body MI. The fitting 26 can be a cap on the end of a support arm, not shown; and also, the upper part of the cap, above the lower end of threads 12 omitted. A large nut, not shown, screwed onto part 11 and down against the remaining ring-shaped part of the originally assumed cap then holds the parts in assembly with the support arm (not shown) jointed with said ring part.

Fitting 26 also has an air passage 34 communicating with annular port 113 and with conduit 35 which supplies air under pressure, which may be in the range of 3580 psi, depending upon the scale of the head, or the degree of atomization required. The air port 13 is in the form of an annular groove encircling the body port 11. A circular series of vertical air holes 39 are drilled between the inner end of bore 16 and the annular groove 13. These holes may be, for example, 12 in number and of adequate bore to assure unrestricted flow. They supply a uniform flow of air down the bore 16, in the cross-sectional form of an annulus.

A plug 40 mounted coaxially in body 11 has a coaxial duct or passage 42 for oil, grease, or liquids which is aligned with and communicates with the duct or pas sage 23 and 32. The pin-like upper end extremity 41 of the plug is closely received in and aligned by the counterbore 22. Just below the pin 41 the plug has an enlarged threaded section 44, and below that a further enlarged cylindrical body 45.

Three very thin, flat, radially-disposed struts 46 at spacing extend vertically downward from the lower end of body 45, outside the projected area of the duct 42, and carry at their lower ends a flat imperforate oil deflection plate 48, preferably an annular disc, whose center is aligned with the duct 42. The lower side of this disc may have a cross bar 49 by which the plug may be conveniently grasped during assembly or disassembly.

The plug body 45 fits slideably into a sleeve 50, and engages at its upper end an internal shoulder 52 at the upper end of the sleeve. A milled nut 53 screws onto the upper end part 44 of the plug, and seats downwardly against the upper end of the sleeve 50. The lower end of sleeve 50 carries a head plate 55 in the form of a flat annular flange, and the periphery of this member 55 has an upwardly-turned cylindric flange 57 which is very closely, but slideably, received inside the counterbore 19. The bottom of this counterbore may serve a positioning stop. The flange 55 is positioned a short distance, in this instance about 0.010 to 0.030 inch, above the disc 48, to allow oil to flow radially at all points as it emerges from under the flange 55 and above the disc 48, over the disc edge 49. The flange 55 is provided, just outside the circle of the disc 48, with an annular pattern of very small, closely-spaced, outwardly angled, air discharge ports 60. Typically, these ports may be about 48 in number, have a diameter of 0.017 inch, and be at an angle of typically 45 to the longitudinal axis of the body 10. Angles within a range of 30-60 have been used successfully, however.

An annular spray head or nozzle 62 is screwed onto the threaded tubular member at the lower end of body 10, and holds sleeve 50 and plug 40 in place. This head 62 thus has a threaded bore 63 to receive member 15, and has an annular ledge 64 at the bottom thereof which is abutted by a narrow outer edge portion of the underside of flange 55. The ledge 64 has a sharp circular edge 66, below which is a downwardly divergent or flared flow control skirt or surface 69 that leads from the edge 66 to a terminal bounding edge 70a at the intersection of surface 69 with the horizontal bottom 70. The flared surface 69 may be substantially conical, but with local modifications, as at 71 in H6. 2, to achieve the modified spray patterns of the present invention.

The operation of the spray head will be described first with the assumption of a substantially conical skirt or control surface 69, at 45 to the longitudinal axis of the spray head, and without modification as at 71, so that a 90 atomized spray cone will result. This angle may range between about 60 and 1 10, or thereabouts. After that will be described the improvements of the present invention, which will produce a spray cone with, say, a basic 90 central angle, but with modifications which square the corner portions of the 90 cone.

In the basic operation of the spray device, then, air under pressure is turned on an instant before the start of the pumping of a predetermined charge of liquid, cooking oil or grease, into the duct of the spray head. The total charge of this liquid goes through the spray head in one almost instantaneous burst, consuming perhaps a few hundredths of a second of time; and the liquid charge being emitted, the pressurized air is then cut off. Proper valving and timing to accomplish this sequence cycle is within the skill of the art and need not be disclosed herein for an understanding of the present invention.

It will thus be seen that charges are discharged in short intermittent bursts. The pan P may be stationary, or moving on a conveyor C, at the time it is coated with the oil. because of the very short duration of the burst of spray.

Considering the operation in more particular, as the oil, other liquid, or grease, exits from the lower end of the duct 42, it strikes the face of the deflecting plate or disc 48 and is turned radially outward in all directions through the annular port between disc 48 and flange 55, flowing off and past the edge of disc 48, and in contact with the flange 55. The radially outwardly flow ing disc" of liquid will be seen to decrease in velocity proportionally with the increase in radius, because of increasing cross-sectional area. The air ports 60 discharge finc streams of air at high pressure and velocity against and through this thin disc or layer of liquid. A large proportion of this liquid oil, thus impinged upon by the fine, high velocity air streams resulting from the high pressure of the air fed to the device, is broken up, atomized into fine spray particles, and thus blown downwardly in an expanding pattern. Some liquid particles are emitted in generally downward direction off the edge of the disc 48 as the radially flowing liquid passes thereover. Finally, and most importantly, another part of the expanding liquid layer, clinging to the underside of the flange even after passage over the air ports 60, impinges upon the conical control surface 69, and thence changes direction to run down this surface, and go off the lower bounding edge 71a of this surface at its intersection with the horizontal face 70.

The liquid thus flowing down the substantially conical face 69 would go off the lower edge 71a thereof in a finely atomized spray with a relatively well-defined conical outline. The spray thus provided would thus be in the form of an expanding cone, filled with particles of atomized liquid which are directed down the cone to fill the pan with adequate uniformity. The particles run together on the surface of the pan, affording an oil or other coating of the requisite uniformity and thickness.

It will be seen that the invention supplies the atomized particles which make up the total spray cone from several sources within the spray head. This results in pressure gradients across the spray cone, but these gradients reduce in successive sections across the cone, with the result that towards the large end of the cone, the liquid particles have a uniformity of distribution that results in a deposit of liquid particles on the pan with the right density to assure the desired coating.

To achieve a substantially square spray outline, in accordance with the present invention, the conical flow surface 69 is modified at four locations, apart, by forming the conical surface with obtuse dihedral angled indentations 76. Thus at each of such four 90-spaced locations, a radial cut is made along a straight bottom line 77 which is at substantially 60 to the longitudinal axis of the device and which intersects, or nearly or substantially intersects, the upper circular edge 66 at the top of the conical flow surface 69. This bottom line 77 intersects the horizontal bottom surface 70, and the indentations 76 thus have flat plane faces 78 which intersect one another, as dihedral angle planes, at the bottom edge line 77. In the present embodiment, which has given the desired result, this dihedral angle is substantially Thus, I have a substantially conical, or frusto-conical, flow surface 69, at a preferred angle of 45, interrupted at 90 intervals by an indentation 0r valley defined at the bottom by a straight edge line 77 at an angle of substantially 60 in a radial plane, and provided with plane faces 78 meeting at the edge line 77 and thus forming an obtuse dihedral angle, which in the illustrative embodiment is substantially 130. The conical surface 69 and the plane faces 78 intersect one another along curved boundary lines 80. It will be noted that in a radial plane, the conical surface 69 makes an angle of substantially 45 with the longitudinal axis, and that in any radial plane intersecting a plane face 76, the angle with the axis is substantially 60, a difference of in regions in which a radial plane intersects both a conical surface area 69 (at 45) and then a plane face area 78 at 60 (FIG. 7), the radial liquid flow along the flow surface continues to remain attached to the flow surface over and beyond the 15 deflection angle at the curved boundary lines 78. Thus, in these regions, the spray is emitted at progressively increasing angles in directions toward the valley lines 77, so as to square out the conical spray at four points spaced 90 apart. Thus, with the shapes and angles described and illustrated, the emitted spray cone is modified to substantially the shape of a four-sided pyramid, such as conforms relatively closely to the outline of a square pan. Substantially rectangular spray patterns are accomplished by spacing the indentations as though they were at the four corners of a rectangle which is similar to the rectangular pan to be used.

I claim:

1. A spray head for spraying atomized particles of oil, grease or the like in a solid spray pattern, characterized by a rectangular outline, comprising:

a nozzle member having a divergent, frusto-conical spray discharge surface adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern,

four circumferentially spaced indentations in said frusto-conical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frustoconical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle.

2. The spray head according to claim 1, wherein said rectangle is a square.

3. The spray head according to claim 1, wherein said obtuse dihedral angles are of the approximate order of 130.

4. The spray head according to claim 1, wherein said frusto-conical surface is at an angle of the order of 45 to said longitudinal axis, and the angle between said axis and said edges of said dihedral angles is of the order of 15 greater.

5. The spray head of claim 4, wherein said dihedral angles are of the approximate order of 130.

6. The spray head of claim 1, whereinthe angle between said longitudinal axis and said frusto-conical surface is of the order of 45, and with said edges of said dihedral angles is of the order of 60, and wherein said dihedral angle is of the order of 7. The spray head according to claim 1, including also:

means located inside the smaller end of said divergent frusto-conical surface for projecting radially outward through a 360 angle a layer of oil, grease or the like, and

high pressure air jet means directed angularly outwardly and downwardly at and through the peripheral region of said layer just inside said smaller end of said divergent frusto-conical surface.

8. In a spray head for spraying atomized particles of oil, grease, or the like in a solid spray pattern having a rectangular outline, and having a nozzle containing a frusto-conical spray discharge surface therein adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern, and having also means located inside the smaller end of said frustoconical surface for projecting radially outward through a 360 angle a layer of oil, grease or the like, and high pressure air jet means directed angularly outwardly and downwardly at and through the peripheral region of said layer just inside said smaller end of said divergent frusto-conical surface, the improvement comprising:

four circumferentially spaced indentations in said frusto-conical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frustoconical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle.

9. A spray head for spraying atomized particles of oil, grease or the like in a solid spray pattern, characterized by a rectangular outline, comprising:

a nozzle member having a divergent, frusto-conical spray discharge surface adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern,

not more than four circumferentially spaced indentations in said frusto-conical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frusto-conical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle. 

1. A spray head for spraying atomized particles of oil, grease or the like in a solid spray pattern, characterized by a rectangular outline, comprising: a nozzle member having a divergent, frusto-conical spray discharge surface adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern, four circumferentially spaced indentations in said frustoconical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frusto-conical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle.
 2. The spray head according to claim 1, wherein said rectangle is a square.
 3. The spray head according to claim 1, wherein said obtuse dihedral angles are of the approximate order of 130*.
 4. The spray head according to claim 1, wherein said frusto-conical surface is at an angle of the order of 45* to said longitudinal axis, and the angle between said axis and said edges of said dihedral angles is of the order of 15* greater.
 5. The spray head of claim 4, wherein said dihedral angles are of the approximate order of 130*.
 6. The spray head of claim 1, wherein the angle between said longitudinal axis and said frusto-conical surface is of the order of 45*, and with said edges of said dihedral angles is of the order of 60*, and wherein said dihedral angle is of the order of 130*.
 7. The spray head according to claim 1, including also: means located inside the smaller end of said divergent frusto-conical surface for projecting radially outward through a 360* angle a layer of oil, grease or the like, and high pressure air jet means directed angularly outwardly and downwardly at and through the peripheral region of said layer just inside said smaller end of said divergent frusto-conical surface.
 8. In a spray head for spraying atomized particles of oil, grease, or the like in a solid spray pattern having a rectangular outline, and having a nozzle containing a frusto-conical spray discharge surface therein adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern, and having also means located inside the smaller end of said frusto-conical surface for projecting radially outward through a 360* angle a layer of oil, grease or the like, and high pressure air jet means directed angularly outwardly and downwardly at and through the peripheral region of said layer just inside said smaller end of said divergent frusto-conical surface, the improvement comprising: four circumferentially spaced indentations in said fruSto-conical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frusto-conical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle.
 9. A spray head for spraying atomized particles of oil, grease or the like in a solid spray pattern, characterized by a rectangular outline, comprising: a nozzle member having a divergent, frusto-conical spray discharge surface adapted to define and emit an expanding spray of the atomized particles in a rectangular pattern, not more than four circumferentially spaced indentations in said frusto-conical surface, each defined by two flat faces making an obtuse dihedral angle with a substantially straight bottom edge line, a prolongation of whose edge substantially intersects the longitudinal axis of symmetry of said frusto-conical surface and makes a greater angle with said axis than does a line substantially intersecting said axis and lying substantially across and contained in said frusto-conical surface, said indentations being so circumferentially spaced that the edges of said dihedral angles terminate at their radially outward ends in points which define a rectangle. 